Overrunning Alternator Pulley

The overrunning alternator pulley (OAP) is designed to decouple the rotor from the deceleration forces and allow the alternator to overrun, thus alleviating much of the stress on the belt. It has a one-way clutch inside the pulley, allowing the alternator’s rotor to coast to a stop position when the engine is shut down, eliminating the possibility of slipping. QRS OAPs reduce belt vibration, noise, load and tensioner movement, increasing the lifespan of the system.